Download Three Types of Muscles

NERVOUS SYSTEM
CENTRAL N.S.
brain & spinal cord
PERIPHERAL N.S.
errything else
MOTOR DIVISION
efferent nerves
SOMATIC N.S.
voluntary*
SENSORY DIVISION
afferent nerves
AUTONOMIC N.S.
Involuntary*
SYMPATHETIC
“Fight-or-flight”
PARASYMPATHETIC
“Rest-n-digest”
• control of skeletal muscles with conscious effort
• the end neurons connected to the muscles release
the neurotransmitter Acetylcholine, causing
myofibrils to contract
THREE TYPES OF MUSCLES
- Skeletal
- Smooth
- Cardiac
AXON TERMINAL
MUSCLE
MYOFIBRIL
/ MUSCLE FIBER
/ MUSCLE CELL
SYNAPTIC
CLEFT
Acetylcholine
(Ach)
•
•
•
•
Involuntarily reaction to a
stimulus
sensory neuron sends signal
to spinal cord; spinal cord
sends message to muscle
bypasses the brain
Evolutionarily evolved for
time-sensitive reactions
• controls smooth muscles without conscious effort
• Regulates functions of our internal organs
• Heavily related to the Endocrine System
• blood pressure, heart rate, breathing rates, body
temperature, digestion/metabolism, water
balance, the production of body fluids (saliva,
sweat, and tears), urination, defecation, sexual
response, etc.
• a cluster of neurons with a
common purpose
• somatic ganglia – bundles of
nerves connected to skeletal
muscles
• sympathetic ganglia vs
parasympathetic ganglia
• the sympathetic and
parasympathetic systems
innervate the same organs
but have opposite effects
Norepinephrine
• increased heart rate
• dilated blood vessels
• dilated airways
• dilated pupils
• activates sweat glands
• slows “less important”
processes such as digestion